Coil-spring.



PATENTED FEB. 12. 1907 J. B. KNUDSBN.

COIL SPRING.

APPLICATION FILED MAY 12,1906.

yzlizewmzimw 1W UNITED STATES PATENT OFFICE.

COIL-SPRING- Specification of Letters Patent.

Patented Feb. 12, 1907.

Application filed May 12, 1906. Serial No. 316.450.

To ail whom it 11mg concern:

Be it known that I, JACOB B. KSL'DSEN, a j citizen of the United States, residing at Dal- 1 ton Station, in the county of Cook and State of Illinois, has invented certainnew and useful Improvements in Coil-Springs, of which the following is a specification.

This invention relates to methods of forming coil-sprin s; and the articular object of I the method w ln'chforms the sub j cot-matter of this application is to provide a coilspring that will not be detempered by long'exposure to heat, that will possess sufiicienttension or resiliency for many purposes, that can be cheaply manufactured, and that may have the ends of its outer coils merge with the adjacent coils or with a flange-ring, as shown in the drawings. My spring is especially adapted for use in steam or hot-water valves, and when so used 5 retains its efliciency and resiliency iudefinitely, though. springs made by the usual methods soon lose their resiliency when sub- I jected to this test.

It is well known that coil-springs as commonly made lose their temper when subject-ed to a certain degree of heat, and hence become i so impaired as to be practically useless until rat-tampered. By my method coil-springs are produced that are without temper. as the term is commonly used, and yet possess and retain constantly their resiliency though subjected for a long time to a high degree of either nlioistor; dry heat. Yhile thg resilient ua ities o s ma e accor v to my inethod are limited than t liose produced in the usual anner, they have 5 and constantly retain suflicient life and resiliency to render them efiicient in various positions and under a wide range of conditions.

In the accompanying drawings I have illustrated a special form of coil-sp 0 produced by my method for the purpose of ring ing out one of the advantages of such method.

In said drawings, F' e 1 shows the spring in elevation. Fig. 2 s ows it invertical sec- 5 tion, and Fig. 3 isa top plan view.

Referring to the drawings in detail, it will be seen that the spring is made up of a plurality of coils 4, each of which is rectangular l in eras-section, and that the upper coil merges withan annular ring 5, formed with 5 an inwardly-extending flange 6, which may i provide a seat or hearing for some part in tended for use with the spring. If made in the ordinary way, it would be quite difiicult,

i if not impossible, to form this wide fiat ring integral with the spring-coils. The customary method of getting a similar result is to provide a separate ring and secure it to the spring. 'I he lowermost coil of the spring shown merges with the coil above it, forming a closed spring at this end. W'ere this spring made from a steel bar bent to the shape shown, the free end of the bar would have to be welded to the adjacent coil, 8. more or less expensive operation. I do not with, however, to confine myself to the particular form i of spring shown and described, since it may be made with free ends, as inordinarysprings,

; or otherwise, as desired, and still possess very valuable advantages not possessed by springs made by the usual methods.

My invention involves making the spring in the form desired in one operation by casting it from a suitable two-piece pattern ina mold-box with a sand core in the same manner that any other cylindrical casting would be produced. The molten metal is preferably iron or steel, or, so far as I now know,

might be certain other metals havin suflicient hardness. I have made springs by this casting method from iron and subjected them to severe and prolonged tests and found that they maintain their efliciency under conditions as to heat, pressure, and torsional strain that would render useless the ordinary tempered springs of commerce.

Having thus described my invention, what I claim is-- 1. As a new article of manufacture, a coilspring composed of cast metal.

2. As a new article or manufacture, a coilspring composed of cast metal and having its respective ends integral with the next adj acent coil.

3. As a new article of manufacture, a coilspring composed of cast metal having an annular flange formed integral with an end coil.

4. As a new article of manufacture, a coilspring composed of cast-iron.

In testimony whereof I afix my signature in presence of two witnesses.

J ACOB B. KNUDSEN. 

